FISA Probable Cause Standard Is Different From The Standard for Criminal Warrants

Foreign Intelligence Surveillance Act ("FISA") intercepts may contain national security information. If an aggrieved person (usually the target of the surveillance) is charged with a crime and seeks discovery of the FISA applications or orders or other materials, alleging the surveillance was unlawfully acquired or not in conformity with the FISA Court's authorization, 50 U.S.C. § 1806(e), (f), the Attorney General could prevent discovery by filing an affidavit declaring that disclosure or an adversary hearing "would harm the national security of the United States," in which case the federal district court reviewing the defendant's motion must "review 'in camera' and 'ex parte' the application, order, and such other materials as may be necessary to determine whether the surveillance of the aggrieved person was lawfully authorized and conducted." See United States v. El-Mezain, 664 F.3d 467, 564 (5th Cir. 2011) (quoting and citing 50 U.S.C. § 1806).